title: Basement membrane (type IV) collagen is a heteropolymer.
abstract: Type IV collagen was isolated in high yield from bovine kidney cortex. The protein revealed Mr = 380,000 and contained, in a 2:1 ratio, two different disulfide-linked polypeptide chains, C-1 and D-1 (Mr = 125,000). Carboxymethyl-cellulose chromatography before and after reduction proved that the two polypeptide chains are arranged in a single triple helical molecule with the chain composition (C-1)2(D-1). The disulfide bridges appear to be located 180 amino acid residues from the NH2 terminus of the chains.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001485:Basement Membrane / Q000032:analysis*; D002417:Cattle; D003094:Collagen / Q000302:isolation & purification*; D005455:Fluorescent Antibody Technique; D005779:Immunodiffusion; D007672:Kidney Cortex / Q000032:analysis*; D046911:Macromolecular Substances; D008970:Molecular Weight
chemical_list: D000596:Amino Acids; D046911:Macromolecular Substances; D003094:Collagen